I've caved and I've picked it up. I got a chance to play for two hours today and it's pretty good so far.
I had misgivings since I'm a Lord of the Rings purist and I consider the movies to be on the verge of heresy. This game does stray a bit from what I would consider canon but with a little suspension of disbelief it's definitely playable by a purist (at least the type who like me can tell the difference between a game adaptation and the source material).
The game makes use of the setting and the lore and builds up on that to cater to its narrative which I won't spoil here. Let's just say that you're playing a ranger from Gondor named Talion who ends up stuck (quite appropriately considering the title of the game) in Mordor. That sounds pretty hardcore considering the Land of Shadows is the last place in Middle Earth where a Ranger would want to go on vacation.
The gameplay is rather interesting and it's difficult not to think about the Assassin's Creed series when playing this title. In fact it looks pretty much like Assassin's Creed in Mordor until you actually play the game and notice some differences in the way the controls feel. Still, it's definitely a game that caters to the same audience who would enjoy some sort of free roaming experience, hunting for collectibles and planning out assassinations.
Ironically here lies the main problem. After two hours of playing the game I can say I'm enjoying it a lot but I have to admit that I really like the Assassin's Creed series (minus the annoying Abstergo sequences in which you play in modern times). The reason why I'm bringing this up is simple: in order to really have fun with Shadow of Mordor you have to be able to enjoy killing orcs by the dozen because that's what the game is about. From what I can tell so far the quests are mostly about killing more orcs. Once you accept that fact it's possible to recognize that the game is really good at what it does.
There is definitely something cool about playing a badass LotR Ranger who fights like good old Aragorn with some moves that can only remind us of the Witcher (or maybe Batman from the Arkham series). At first it may seem pretty easy but things can get more interesting once you start running into orc captains. These guys are tough and if you're not lucky you can end up facing several at the same time (in which case a tactical retreat may be the wise option). The interesting thing about these orc captains is that they are mostly randomized and have different strengths and weaknesses, they can also have some specific ambitions and goals. They can also rise within the ranks and end up near the top of the Dark Lord's armies.
Obviously I haven't been able to see the whole extent of this system but it looks like it adds a much needed dynamic factor to a recipe that could otherwise grow stale pretty fast (unless you're a big fan of collectibles).
You can get into real vendettas with these captains as some of them can cheat death making their ultimate demise all the more satisfying.
I will probably have more things to say as I progress through the game. Visually it is a treat and it runs better than the Witcher 2 on my computer. Some characters may look a bit drab (I'm thinking of human slaves but in their case that may be appropriate) but the orcs are just incredible, they have that great orc vibe and a certain uniqueness due to the randomization which really help with immersion IMO.
Random elements in a sandbox game usually make for great entertainment value so hopefully the main story won't be too much of a letdown.
Last but not least, I haven't seen or read anything about dragons so far. I can't tell you how nice it is to play a fantasy game that doesn't showcase overgrown fire-breathing lizards.
Just to give you an idea here are some screenshots I've found on the net that show the way orc captains are presented in the game: